Reboot

• Force a reboot from a host's menu, or from the reboot needed banner. Servers restart at once; workstations and laptops get 10 minutes of warning by default, announced through the system's shutdown broadcast with your optional message.
• After a patch that needs a restart, the policy's Reboot section decides: do nothing, reboot automatically in the maintenance window, or warn users 30 minutes ahead and then reboot.

While a host restarts it is in planned downtime (status maintenance) for the warning delay plus 15 minutes, so your supervision does not raise false alarms. When the agent reports from the new boot, the task succeeds and the host goes back online. If it stays silent past the window, the reboot task fails, the host turns alert and the critical event host did not come back after reboot is sent.